The air/fuel sensor, located in the exhaust system, may be damaged by moisture in the exhaust resulting in illumination of the Check Engine Light. Replacing the damaged air/fuel sensor and updating the powertrain control module (PCM) software should correct this concern.
Car Problem Reports
Honda Civic Moisture Damage to Air Fuel Sensor
Honda Civic Problem
Model Year Affected: 2006
Visitor, 2006 Honda Civic, 185,130 mi
Engine light came on. Honda service diagnosed as Air Fuel Sensor gone bad. Testing, part and service cost $413.00. Really only problem after all these miles.